1. Field of the Invention
The present invention relates to a micromanipulator for a fine control apparatus such as glass electrode or the like which is positioned under a microscope by remote control using hydraulic pressure.
2. Prior Art
In the field of basic medical science or biotechnology, a micromanipulator is used when retaining, suctioning, pouring, dividing, or performing other procedures on organs or the cellular structure of creatures, eggs, or the like. The micromanipulator is finely controlled for exact positioning under a microscope.
However, when an operator directly touches an operating handle of the micromanipulator in actual operation, any trembling of his fingers is transmitted to the micromanipulator in magnified degree. The operator is required to use utmost care and skillfulness in operation. Therefore, known remotely controllable fine control micromanipulators use hydraulic pressure.
FIG. 10 illustrates the structure of a conventional cell handling apparatus.
In FIG. 10, reference numeral 91 indicates egg cells. Reference numeral 93 indicates a platform on which a petri dish 92 containing a testing liquid for the egg cells 91 is placed. The egg cells 91 are immersed in the testing liquid in the petri dish 92, Reference numeral 94 indicates a fixed supporting part for the egg cells 91. The fixed supporting part 94 includes a micromanipulator 95 positioning the egg cells. The fixed supporting part 94 also includes a lighting system 96 for observing an illuminated image of the egg cells 91. The egg cell positioning apparatus is placed on a vibration proof mat 97.
The micromanipulator 95 is provided with a microtool 98, such as a glass electrode or the like, specifically designed for egg cell positioning. The foremost end of the micromanipulator 95 is provided with a three-dimensional displacement mechanism. An operator activates the three-dimensional displacement mechanism by means of hydraulic pressure generated by a joystick 99.
The joystick 99 is formed such that an operating handle 102 is suspended from the foremost end of a supporting frame 101 and the joystick 99 rocks in two horizontal directions 103 crossing at right angle as indicated by the arrows. The rocking motion of the joystick 99 is translated to the three-dimensional displacement mechanism through a transmission part 104 by means of hydraulic pressure.
The operating handle 102 is provided with a conversion part 105 to convert the rocking motion in two horizontal directions 103 to mechanical displacement in a horizontal plane. The conversion part 105 is provided at a position where said conversion part 105 is connected to the supporting frame 101.
Previously it was customary to provide the operation handle 105 projecting upwardly from the conversion part 105, but nowadays a suspended type joystick has been preferably used in most cases.
In a conventional apparatus, when the cells are to be moved in a vertical direction by the three-dimensional displacement mechanism, a mechanism of fine control in vertical direction is also provided for the three-dimensional displacement mechanism.
In known three-dimensional displacement mechanisms operated by a fine control joystick using hydraulic pressure, the operator displaces the operating handle of the joystick in a desired direction to displace the foremost tip end of a microtool disposed in the micromanipulator so as to observe the cells through a microscope. The operator must have a sense of how to displace the microtool of the micromanipulator in horizontal plane while the handle of the joystick is inclined for proper vertical position. This has been a confusing and sensitive problem in practical operation.